dynamic_cast operator

dynamic_cast operator

Polymorphic cast of class type objects

postfix-expr := dynamic_cast < type-id > ( expression )

The dynamic_cast operator performs a
polymorphic
cast on a pointer or reference to an object of class type. If
expression is a pointer or reference to a base
class, type-id can be a pointer or reference to
a derived class. If the dynamic type of the object is not that of
type-id or a class derived from
type-id, the cast fails. If
expression is a pointer, failure returns a null
pointer; if expression is a reference, failure
throws std::bad_cast. Casts from a derived to an
unambiguous, accessible base class always succeed.

If expression is a null pointer, the result is a
null pointer. If type-id is a pointer to
void, the cast succeeds and returns a pointer to
the most-derived object that expression
represents.